Real simple. Keep your fingers away from the germs.
The germs keep multiplying, and you have to keep adding fingers.
How long can you last!
Best used in the privacy of your own home, some very strange hand combinations can ensue.
Also sporting an exciting two player mode, its ideal for sparking new romances. Simply suggest a game with the object of your desires, finger touching is inevitable, a longing look into the eyes and voila, job done. Probably not a game to play two player with two burly men however, that kind of finger intimacy many find threatening!